Domain-general Grit has been criticised as being indistinguishable from Conscientiousness and as a weaker predictor than Cognitive Ability. Given the recent rise of L2 Grit literature -- a domain-specific form of Grit in language learning -- we examine whether these criticisms of general Grit are also applicable to L2 Grit. Domain-general Grit, L2 Grit, Cognitive Ability, and Conscientiousness were compared as predictors of language learning outcomes. Data from 182 EFL students were analysed via multiple regression with dominance analyses. L2 Grit was the dominant predictor of L2 academic achievement, L2 engagement, and Ideal L2 Self. L2 Grit outperformed domain-general Grit in all models tested. Methodological concerns regarding domain-general Grit and Conscientiousness did not apply to L2 Grit. Cognitive Ability was an important predictor of L2 learning, but was mostly outperformed by L2 Grit. This study advocates for the use of L2 Grit above that of domain-general Grit in L2 learning research.